Charge-preparing apparatus.



W. R. McKEEN, 1a.,

CHARGE PREPARING APPARATUS. APPLICATION FILED JULY]; 1909.

Patented June 12, 191?.

2 SHEETS-SHEET l- W. R. McKEEN, JR. CHARGE PREPARING APPARATUS.

APPLICATION FILED JULY 1, I909.

Patented June 12, 1917.

WITNESSES WILLIAM It. MUKEEN, JR., 0F OMAHA, NEBRASKA, ASSIGNOR T0 MCKEEN MOTOR CAR COMP, 0F OMAHA, NEBRASKA, A CORPORATION OF NEW JERSEY.

CHARGE-PREPARING APPARATUS.

Specification of Letters Patent.

Patented June 12, 1917.

Application filed July 1, 1909. Serial No. 505,407.

To all whom it may concern:

Be it known that I, WILLIAM R. MCKEEN, J12, a citizen of the United States, residing at Omaha, in the county of Douglas and State of Nebraska, have invented certain new and useful Improvements in Charge- Preparing Apparatus, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention pertains to charge-forming apparatus or carbureters for internal combustion engines, and consists in various novel features and combinations hereinafter set forth, whereby the charge delivered to the engine is automatically conditioned to suit the requirements of the engine as determined by speed and duty, and control of the engine through manipulation of the throttle, in a manner closely simulating steam engine practice, is made possible.

In the accompanying drawings wherein is shown one of various possible embodiments of the invention,

Figure 1 is a front elevation, certain parts being broken away in order to disclose the structure more clearly;

Fig. 2 is a sectional elevation taken substantially on the line m-a: of Fig. 1;

Fig. 3 is a detail side elevation of certain parts shown in Fig. 1;

Fig. 4 is a detail plan of an air valve or gate;

Fig. 5 is a detail view of a hydrocarbon valve.

Similar reference characters refer to similar parts throughout the several views of the drawings.

Referring now to Fig. 2 of the drawings, there is shown a casting 1, jacketed at 2, which forms a chamber 3, for purposes hereinafter described, and a conduit l adapted to lead air thereto.

Mounted upon casting 1 is a casing 5 having formed therein a shoulder 6 adapted to support an inner casing 7 telescopically fitted therein and removable with respect thereto. This inner casing is formed open at its lower end, but closed at the top, as shown at 8, and provided with a handle 9 and lateral air ports 10. Within casing 7 is formed a cylindrical screen 11 having secured therein a series of curved screens 12 alternately disposed in opposite directions, as indicated in the drawings. This screen construction is set forth and claimed in applica'tion Serial No. 417,764, filed in my name on the 25th day of February, 1908, hence is not claimed herein except in connection with the casing and air inlets.

Pivotally mounted within suitable bearings in the casing or conduit 4 is a squared shaft 13 having thereon a crank 14 best shown in Fig. 3 of the drawings. This crank controls the position of an inclined air-valve 15 which fits freely about the squared portion of shaft 13 and normally rests against shoulder 16 as a stop. Valve 15 is urged toward closed condition by a spring 17 interposed between crank 11 and a bell crank lever 18 provided with handle 19. The latter lever rocking upon the stud 20 may be adjusted in position to vary the tension of the spring and held at the desired point by a set-screw 21, clamping the same against the slotted quadrant 22. In this manner the air-valve is normally held closed .and is opened by the action of the inrushing air, as it is so pivoted as to have a differential action, the shaft 13 being offset from the center of the valve. There is provided, moreover, a port 23 through the valve whereby a suitablev amount of air is freely admitted even though it enter at such rate as to have no effect in opening the valve.

The air passing valve 15, is drawn through the curved conduit 4 toward the chamber 3, a portion of which is formed by the casting 1 and a portion by a flanged casting 24 bolted thereon, as best shown in Fig. 2. In this chamber are positioned a plurality of inclined screens 25 converging upwardly as shown. These screens are so disposed as to extend across the path of the entering air and thus force the same to pass therethrough, as hereinafter described in detail.

it will be noted, however, upon referring to Fig.2, that only the uppermost screen of the series extends to the upper wall of chamher 3, hence a limited volume of air may pass above the other screens to and past the throttle valve 40, and come in contact only with the upper screen and the gasolene thereon. This 1 find important when the engine is turning over very slowly, and the suction and consequent air current are light,

as under such conditions the series of screens would offer an undue resistance to the passage of the air, and result in inadequate supply of air or mixture to the engine.

Mounted or formed upon the casting 1 is a jacketed tank 26 adapted to receive the gasolene or other charging element. This tank is provided with an inlet 27, leading from any desired source of supply. lVithin the tank or float chamber is arranged a float 30, preferably of spun copper or the like, provided with an axial rod or stem 29, the lower end of which passes through the inlet opening at the bottom of the tank and bears normally upon the top of valve 28. Stem 29 passes through a removable head to insure its rectilinear movement, and beneath the valve 28 is positioned a conical, spiral spring 31 tending to urge, the same into closed condition. By means of this apparatus there is provided a substantially constant level of hydrocarbon in the tank 26, since upon lowerin the tan the float will fall, and its stem 29, by reason of its bearing thereon, will open valve 28 and thus draw from the main tank a sufficient amount to raise the float to its normal position, as hereinafter described in detail.

The lower portion of tank 26 is connected by a passage 32 with a nipple 33 which forms a seat for a needle valve 34 threaded in position, as indicated in Fig. 1 of the drawings. This valve is controlled by a spindle 35 mounted within a supporting bracket 36 at such an angle as to be conveniently accessible and connected with the valve stem 37 by a Hookes joint. The handle or grip of the spindle 35 is graduated as shown, and there is provided an index 38 and a set screw 39 for holding the valve in adjusted position. By the latter means the flow of the hydrocarbon may be adjusted to the desired rate, and this rate maintained irrespective of the extent of the jarring or vibration to which the parts are subjected. It may be noted at this point that the normal level of hydrocarbon within the tank 26 is preferably such as to cause a discharge by gravity through the valve 34 upon the latter member being opened. It may,,also be noted at this point that the valve 34 is so positioned as to discharge directly upon the screens 25 at their upper portions where they are closely disposed with respect one to another by reason of the converging disposition above noted.

Within the casting 24 is provided a suitable throttle valve 40 controlled in any desired manner to feed the carbureted mixture to the engine at the desired rate. From this valve the charge is led to the cylinder or cylinders of the engine through any desired form of conduit.

A suitable drip port is provided at 41 to of the level of hydrocarbon within drain away and prevent the accumulation of I gasolene, if forany reason it should be fed too rapidly to the carbureting chamber.

Recurring now to the description of the mechanism for automatically feeding hydrocarbon to the tank 26, it is to be noted'that in many former types of carbureters in which it is aimed to maintain at some point a constant level of hydrocarbon, this result is not attained, by reason of the effect of the inflowing liquid upon the valve by which it passes. The current of hydrocarbon, partially by its friction against the valve and more particularly by its inertia, upon flowing against and being deflected by the valve, tends to move the latter part either toward or away from its seat. This tendency, which often seriously affects a delicately balanced valve, varies with the rate at which the hydrocarbon is being fed, and thus introduces not only a source of error, but a varying source of error into the action of the means by which it is sought to maintain the level constant. In the illustrative apparatus under consideration, the hydrocarbon is led through an annular passage or series of passages 42 into a circular chamber encompassing and concentric with the valve 28, from which chamber it passes into the tank 26. The valve is so formed that this lateral stream acting upon its upper curved or inclined surfaces, exerts a downward effect which neutralizes the upward tendency imparted to the valve by reason of the friction and suction of the fluid. As under this construction the flow of hydrocarbon towardthe passage opening into the base of tank 26 is from all sides alike, and as any closing tendency incident to the friction and suction of the liquid acting upon valve 28 is counteracted by the downward pressure of the liquid flowing over its curved or domeshaped top, it follows that said forces or influences being once properly proportioned and balanced by proper shaping or curvature of the valve, they must remain balanced and counteract or neutralize each other, whatever he the degree of suction or the rate of flow of hydrocarbon into tank 26. In this manner, the valve is controlled as it properly should be by the float 30, in conjunction. in this embodiment, with the spring 31, and the level is accurately maintained constant.

In the use of the above apparatus the following features may be noted: The jackets 2 are preferably filled with jacket water from the engine or other heating medium, whereby the parts are maintained warm and thus adapted for most efficient action. In starting the engine, moreover, in cold weather, if the parts are cold, the casing 7 is removed from casing 5 and the screen therein saturated with gasolene which is ignited to heat the same. The casing 7 is then replaced in position, as shown in Fig.

- 1 ,aaaeea 2, and the air entering through ports 10 is raised to a high temperature in passing through the several heated screens. It is to be noted that in using this portion of the apparatus the complete casing about the screen not only protects the operator in heating the same, but tends to thoroughly conserve the heat.

From the casing 5 the air in proper condition is drawn to the valve 15, and if the engine is just starting or running at slow speed, it is freely admitted through the port 23 in this valve. If, however, the 611". gine is running at normal speed, the inrush-.' ing air will automatically open the differential valve 15 to just such a position as will properly accommodate its inflow. This action is adjusted for different conditions of air or fuel by means of the bell crank lever 18, and this lever being once set, the valve will automatically accommodate itself to variations in speed of the engine. In passing about this inclined valve or through the port- 23, the air is given a whirling movement which is intensified in the curved conduit 4, so that in place of a steady incoming stream, there is a whirling current which contributes materially to the efficient action of the apparatus.

The valve 3a being open to the desired extent the hydrocarbon flows through the passage and drips by gravity upon the screens 25. Upon these members it instantly spreads out across the meshes by the well known action ascribed to the surface tension of the liquid. Each screen upon which the gasolene is delivered, therefore, presents what is in effect a broad and extremely thin sheet of asolene, which, by reason of its great sur ace as compared with its volume, evaporates almost instantly. The inclined and converging disposition of the screens results in each screen being properly fed and the gasolene readily spreading out upon its surface, as above set forth, and there is thus provided even in still air a rapidly developed body of gasolene vapor. When the throttle is opened wide, and a large and rapidly moving current of air is carried through the chamber 3 and past the throttle 10, the evaporation and absorption or difi'usion may take place so rapidly that only the short upper screen, or two or three screens, will receive oil; but when the movement is slower and the volume less, the gasolene, fed at uniform rate, will fall from screen to screen until all the screens of the series become more or less charged therewith, andopen the valve. It will be noted upon referring .to Fig. 2, that the squared shaft 13 is above or on the upper side of the valve 15, and that with the shorter side of the valve it forms a pocket tending to obstruct the passage of the air from the shorter to the longer side of the valve. When, therefore, the valw e is tipped or partially open, that portion of the air flowing to the wider side of the valve, and striking a face inclined in the general direction of travel of the air, is directed. toward the upper ends of the sieves or screens 25, further tending to take such course by reason of this being the shortest or most direct route to the engine cylinders. Hence this larger volume of air strikes first across the upper ends of the screens, and tends to pass between the upper boundaries thereof and the top wall of the shell or casing. The same is true of the. smaller volume of air which passes through the permanent opening 23 when the valve 15 is seated or closed.

That portion of the air which passes to the narrower side of the valve 15 is, by reason of its striking in the pocket above described, and being caused to pass around the upwardly inclined face of the valve, caused to whirl or is thrown into a swirling current which, passing into the curved conduit 4 and filling the same, passes thence through the several screens, and on its way takes up whatever vapor there may be in the conduit 4, and vaporizes and absorbs the gasolene on the screens. The two currents of air separated by the valve 15 combine, and pass the throttle 40 as one uniformly impregnated mixture of air and gasolene vapor.

The inclined position of the screens permitting the main inflowing current of air to pass in considerable degree between the screens, or the space above the screens permitting a considerable volume of air to pass by them until the upper or short screen is encountered, and the provision of a comparatively large chamber in which the slower moving volume of air may swirl and take up the free vapor, all contribute to the production of a mixture suited to the demands of the engin under different conditions. I

The suction induced by the engine is, of course, proportionate to the capacity of the cylinders, and the rate at which the pistons are operated therein. The effective suction is dependent upon the setting of the throttle valve 40, and the efiective area of the air inlet. It will therefore be seen that for a given capacity and rate of movement of the engine, the volume of air drawn through the carbureter will depend upon the setting of the throttle valve 40' If said valve be but slightly open, the permanent port 23 of valve 15 will admit sufi icient air to supply the demand made by the engine. If, howvever, the throttle be opened wider so as to produce greater effective suction, valve 15 will tip or open proportionately and admit more air, and this action will take place throughout the range represented by full closing and full opening of valve 15, the resistance of which to opening is determined by the setting of lever 19, and consequent tension of spring 17. The arm 14 of the valve shaft is so set that its leverage changes but little throughout the range of tipping of the valve, but the angle of the valve changes quite rapidly, and in such a way as to materially decrease the effective leverage of the air tending to turn it.

By proper adjustment of these elements, and by affording abundant air inlet, I am enabled, with the aid of the inclined screens receiving gasolene at the head of the uppermost screen of the series, to produce under each and every adjustment of the throttl that mixture which at the speed of the engine, determined by such adjustment of the throttle, is appropriate and best suited to the speed and duty of the engine, and I am also enabled, Without the use of change-speed gear, to control the engine by the throttle alone through a very wide range of speeds. In practice it is found feasible to control the speed of a vehicle propelled by a gasolene engine provided with this carbu reter solely through manipulation of the throttle, at speeds from about two miles an hour to fiftyor sixty miles an hour, and it is further found that with the engine turning over slowly, and at a rate which with th 'clutch thrown in would represent but about two miles an hour, it is practicable to manipulate the clutch and throw on the full load of the engine, and without change of gear but by merely opening the throttle. to speed the engine up to its maximum.

This great flexibility of control by the throttle is of special and peculiar importance in connection with vehicles for use on railways, and particularly where used upon lines having also th regular steam locomotive service. It enables the vehicle to be readily slowed down, promptly started, quicklyaccelerated, and to suddenly assume its full load when running at low speed.

It is to be noted that by reason of the, conformation of the passage 32, there is a slight siphoning action, such that even if the level in the tank should fall below the highest point of this passage, the feed will be uninterrupted, due to this action. This feed of the fuel is accurately controlled at the desired rate, and upon entering into the carbureting chamber the fuel is instantly spread out, as above noted, thus doing away with any chance of small particles being fiecked over into the cylinder in liquid form, as

- often occurs with carbureters of the well feeding and will produce a relatively large volume of vapor and consequently rich mixture, such as is desirable when starting, or when rapidly accelerating the speed of the engine. The siphon causes such feeding to continue for a relatively long time, even though there be no inflow into the float chamber during such time.

Since with the use of the siphon feed the liquid is drawn from the lower part of the float chamber the gasolene will continue to feed under all tipping of the float chamber which does not raise the. outlet of needle valve 34 above the level of the liquid, and in the event of tipping so as to lower the out let of needle valve 34:, the feeding will continue until the level of liquid in the float chamber falls practically to the bottom 01 the float vessel, or materially lower than would serve to keep up the feed without the siphonic action. Moreover, with the upwardly extending or inclined passage 32 thereis less liability of air being drawn in through the oil passage, and less tendency of the suction of the engine to draw air in above the float, and to cause a suction feed of the gasolene. It is believed that the great eiliciency and steadiness of feed of the carburetcr is due in considerable measure to this siphonic action.

It will thus be seen that there is provided apparatus in which the several aims of this invention are achieved and the above'and many other advantages attained.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the acompanying drawings shall be interpreted as illustrative and not in a limiting sense.

It is also to be understood that the language used in the following claims is intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In apparatus of the nature described,

in combination, means forming a chamber, a plurality of screens disposed in converging relation in said chamber, means adapted to lead air into said chamber, and means adapted to lead a hydrocarbon upon said screens adjacent their converging ends.

2. In apparatus of the nature described, in combination, a casing provided with a chamber; a foraminous diaphragm in said chamber, composed of converging screens; a conduit. adapted to lead air into said chamber; and means adapted to deliver a hydrocarbon upon said diaphragm.

3. In apparatus of the nature described, in combination, a conduit, means adapted to admit air thereto, a source of hydrocarbon supply, and a connection adapted to lead hydrocarbon from said source of supply by gravity into said conduit, said connection being formed and positioned to act as a siphon with certain levels of hydrocarbon in said source of supply.

4. In apparatus of the nature described, in combination, means forming a chamber, a plurality of upwardly converging screens in said chamber, means adapted to lead air into said chamber, a source of hydrocarbon supply having a normal level above the upper ends of said screens, and means adapted to lead hydrocarbon by gravity from said source of supply upon the upper end portions of said screens.

5. In apparatus of the nature described, in combination, carbureting means, a conduit adapted to lead air thereto, a casing upon said conduit, a second casing adapted to fit removably in said first casing and provided with lateral ports for the admission of air, and a screen member in said second casing through which the air is led.

6. In apparatus of the nature described, in combination, carbureting means, a conduit adapted to lead ai'r thereto, a casing upon said conduit, a covered casing adapted to fit removably in said first casing and provided with lateral ports for the admission of air, and a screen member in said second casing through which the air is led.

7. The combination of a shell containing a curved air passage; fuel feeding means; and a plurality of screens located within said passage and oblique to the axis thereof, the top of the uppermost screen being located adjacent the point of delivery of the fuel.

8. In a carbureter, the combination of a feeding mechanism; a plurality of inclined screens located in the air passage adjacent the point of fuel delivery of said mechanism; and a valve located in the air passage at a point in advance of' said screens and mounted to open under the action of the air current and to partially close said passage When the flow of air is decreased.

9. In a carbureter, the combination of a shell forming a curved air passage; fuel feeding mechanism; a plurality of inclined screens located in the air passage adjacent the point of fuel delivery of said mechanism; a valve located in the air passage at a point in advance of said screens and mounted to open under the action of the air current and to partially close said passage when the flow of air is decreased; and

means to warm the air prior to its passage through said screens.

10. The combination of a shell forming a curved air passage; fuel feeding mechanism; a plurality of screens mounted in said passage adjacent the delivery point of said feeding mechanism; and a structure adapted to the passage of air and capable of being heated by external means, removably mounted in the admission end of said air passage.

11. The combination of a shell forming an air passage; fuel feeding mechanism; a perforate structure mounted in said passage adjacent the delivery point of said fuel feeding mechanism and designed to have a large surface area; a valve in said passage in advance of said perforate structure, said valve being urged in an opening direction by the flow of air through said passage, and being adapted to partially close said passage; a spring opposing the complete opening of said valve; means for adjusting the tension on said spring; and a structure comprising a plurality of heat radiating members adapted to be heated by external means, removably mounted in the admission end of said passage.

In testimony whereof I' afiix my signature, in the presence of two Witnesses.

WILLIAM R. MCKEEN, JR.

Witnesses:

HENRY W. E. MAoDANm, C. B. SMYTII. 

